Unlike stimuli used in traditional neurophysiological experiments most natural scenes have many objects that occlude one another. The ability to decompose these scenes into component objects depends on the proper detection and grouping of object parts. This perceptual process, termed figure-ground interpretation is central to the healthy function of the visual system. It has been hypothesized that figure-ground interpretation occurs relatively early in the visual processing stream. Correspondingly, one objective of the proposal is to determine whether neurons in cortical areas V1, V2 and MT are sensitive to the same stimulus manipulations that influence the perception of figure-ground. Results from behavioral studies have demonstrated that the veridical perception of motion in complex dynamic scenes depends upon figure-ground interpretation. Recent neurophysiological data suggest that changes in figure-ground interpretation alter the response properties of directionally selective neurons in cortical area MT. Hence, a second objective of this proposal is to characterize the interaction between figure-ground and visual motion processing in area MT. These objectives will be achieved by the application of several novel visual displays that simulate simple occlusion of one object by another. Use of combined behavioral and neurophysiological techniques will establish a correspondence between perceptual and neural events. Results from these experiments will lead to more refined models of visual processing and aid in the development of artificial sensory systems. In addition, the research will provide important information for the treatment of brain-damaged and disease conditions that disrupt visual function.